| Message ID | 20230524091948.41779-3-boerge.struempfel@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | spi: add SPI_MOSI_IDLE_LOW mode bit | expand |
On 24.05.23 11:19, Boerge Struempfel wrote: > By default, the spi-imx controller pulls the mosi line high, whenever it > is idle. This behaviour can be inverted per CS by setting the > corresponding DATA_CTL bit in the config register of the controller. > > Also, since the controller mode-bits have to be touched anyways, the > SPI_CPOL and SPI_CPHA are replaced by the combined SPI_MODE_X_MASK flag. > > Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com> Thanks for working on this! We used a similar downstream patch for driving NeoPixels with i.MX. I'm happy to see a proper upstream solution. I also have this Python module [1] around for using spidev to drive the LEDs. It would be nice to see support for SPI_MOSI_IDLE_LOW in py-spidev [2] so we could use it there. Though the latter looks a bit like it is not properly maintained anymore. [1] https://github.com/fschrempf/py-neopixel-spidev [2] https://github.com/doceme/py-spidev Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Am Mi., 24. Mai 2023 um 11:47 Uhr schrieb Frieder Schrempf <frieder.schrempf@kontron.de>: > > On 24.05.23 11:19, Boerge Struempfel wrote: > > By default, the spi-imx controller pulls the mosi line high, whenever it > > is idle. This behaviour can be inverted per CS by setting the > > corresponding DATA_CTL bit in the config register of the controller. > > > > Also, since the controller mode-bits have to be touched anyways, the > > SPI_CPOL and SPI_CPHA are replaced by the combined SPI_MODE_X_MASK flag. > > > > Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com> > > Thanks for working on this! We used a similar downstream patch for > driving NeoPixels with i.MX. I'm happy to see a proper upstream solution. > Thanks for your reply. I'm glad to see that there is an interest for this and I'm not the only one, who is working with this. > I also have this Python module [1] around for using spidev to drive the > LEDs. It would be nice to see support for SPI_MOSI_IDLE_LOW in py-spidev > [2] so we could use it there. Though the latter looks a bit like it is > not properly maintained anymore. The python modules looks interesting. FYI: there is already another patch by Chuanhong Guo on the mailing list, which implements a proper driver for neopixel leds. It also allows to add them via DT and access them via sys-fs. It might be an interesting upstream alternative for your python module if it gets accepted. https://lore.kernel.org/lkml/20221212045558.69602-1-gch981213@gmail.com/ > > [1] https://github.com/fschrempf/py-neopixel-spidev > [2] https://github.com/doceme/py-spidev > > Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de> -- Kind Regards, Börge Strümpfel
On Wed, May 24, 2023 at 11:19:45AM +0200, Boerge Struempfel wrote: > By default, the spi-imx controller pulls the mosi line high, whenever it > is idle. This behaviour can be inverted per CS by setting the > corresponding DATA_CTL bit in the config register of the controller. This doesn't apply against current code, please check and resend.
Am Di., 30. Mai 2023 um 14:46 Uhr schrieb Mark Brown <broonie@kernel.org>: > > On Wed, May 24, 2023 at 11:19:45AM +0200, Boerge Struempfel wrote: > > By default, the spi-imx controller pulls the mosi line high, whenever it > > is idle. This behaviour can be inverted per CS by setting the > > corresponding DATA_CTL bit in the config register of the controller. > > This doesn't apply against current code, please check and resend. I wrote this patch against the current master and not the next/master. I'll upload an adjusted patch version momentarily. I'm sorry for the inconvenience. -- Kind Regards, Börge Strümpfel
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 34e5f81ec431..1c4172fcba2d 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -281,6 +281,7 @@ static bool spi_imx_can_dma(struct spi_controller *controller, struct spi_device #define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs & 3) + 4)) #define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs & 3) + 8)) #define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs & 3) + 12)) +#define MX51_ECSPI_CONFIG_DATACTL(cs) (1 << ((cs & 3) + 16)) #define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs & 3) + 20)) #define MX51_ECSPI_INT 0x10 @@ -573,6 +574,11 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx, cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(spi_get_chipselect(spi, 0)); } + if (spi->mode & SPI_MOSI_IDLE_LOW) + cfg |= MX51_ECSPI_CONFIG_DATACTL(spi_get_chipselect(spi, 0)); + else + cfg &= ~MX51_ECSPI_CONFIG_DATACTL(spi_get_chipselect(spi, 0)); + if (spi->mode & SPI_CS_HIGH) cfg |= MX51_ECSPI_CONFIG_SSBPOL(spi_get_chipselect(spi, 0)); else @@ -1743,7 +1749,8 @@ static int spi_imx_probe(struct platform_device *pdev) spi_imx->controller->prepare_message = spi_imx_prepare_message; spi_imx->controller->unprepare_message = spi_imx_unprepare_message; spi_imx->controller->slave_abort = spi_imx_slave_abort; - spi_imx->controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_NO_CS; + spi_imx->controller->mode_bits = SPI_MODE_X_MASK | SPI_CS_HIGH | SPI_NO_CS | + SPI_MOSI_IDLE_LOW; if (is_imx35_cspi(spi_imx) || is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx))
By default, the spi-imx controller pulls the mosi line high, whenever it is idle. This behaviour can be inverted per CS by setting the corresponding DATA_CTL bit in the config register of the controller. Also, since the controller mode-bits have to be touched anyways, the SPI_CPOL and SPI_CPHA are replaced by the combined SPI_MODE_X_MASK flag. Signed-off-by: Boerge Struempfel <boerge.struempfel@gmail.com> --- drivers/spi/spi-imx.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)